<![CDATA[Heavy reliance on fossil fuels has driven the search for renewable energy, including bioethanol produced from lignocellulosic biomass. Although Saccharomyces cerevisiae is the yeast most commonly used for bioethanol because of its high productivity, it cannot efficiently ferment pentose sugars, which restricts its application to lignocellulosic feedstocks. Pichia anomala, a non-conventional yeast able to ferment both glucose and xylose, is therefore a promising alternative. This study compared how well S. cerevisiae and P. anomala produce bioethanol from a sugar hydrolysate of cassava (Manihot esculenta) peel powder. The powder was first delignified with 6% NaOH and hydrolyzed with 3 M H₂SO₄, followed by 72 hours of microbial hydrolysis with Aspergillus niger. Each yeast was then grown for 96 hours under anaerobic conditions at its own optimum (S. cerevisiae: 31°C, pH 4.5; P. anomala: 30°C, pH 5), and ethanol was quantified by HPLC. Microbial hydrolysis raised the reducing sugar content from 2.43% to 6.27%. Cell growth, substrate utilization, and ethanol production did not differ significantly between the yeasts (p > 0.05); however, P. anomala reached a numerically higher ethanol concentration (0.89%) than S. cerevisiae (0.60%), suggesting that it could serve as an alternative fermentative yeast. Fermentation efficiency and ethanol yield were 19.6% and 10% for S. cerevisiae, and 29.2% and 14.9% for P. anomala; both were below values in earlier reports, indicating that the process can still be optimized.]]>
